Apparatus for finishing the surface of cylindrical bodies



4 n w n u n m n u Jan. 16, 1945. GAENZLE 2,367,641

APPARATUS FOR FINISHING THE SURFACE OF CYLINDRICAL BODIES Filed Aug. 22, 1939 2 Sheets-Sheet 1 m i m a Y Jan. 116, 1945. E. GAENZLE APPARATUS FOR FINISHING THE SURFACE OF CYLINDRICAL BODIES.

2 Sheets-Sheet 2 Filed Aug. 22, 1939 We y AW 5 w m L Patented Jan. 16, 1945 r APPARATUS FOR FINISHING THE SURFACE OF CYLIND'RICAL BODIES Luther E. Gaenzle, Lancaster, Pa., assig'nor to Armstrong Cork Company, Lancaster, Pa., a corporation of Pennsylvania Application August 22, 1939, Serial N: 291,287

Claims.

This invention relates to an apparatus for finishing the surface of cylindrical bodies such as rods, tubes and the like and, more particularly, to a device for shaving the outer peripheral sur-' face of hollow cylindrical tubes of cork composition and similar materials to reduce the same to a predetermined and uniform outer diameterfrom end to end while maintaining the wall thickness of the tube substantially uniform throughout its length. In another aspect, this invention contemplates an unique cutter and breaker for performing such function.

In the manufacture of textile cots and similar cylindrical bodies of cork composition, the outer peripheral surface is not always as smooth and true as required due to surface irregularies resulting from nonuniform expansion of the cork granules at the surface. It is customary in such manufacture to grind or otherwise smooth up the outer peripheral surface and common practice has been to finish the bodies on a centerless grinding machine. This finishing process is relatively expensive and does not insure the main-- tenance of a uniform wall thickness when-hollow tubes are being operated upon. Rotary cutters in which there is provided a leading cutting edge and in which the rod or tube to be finished is passed through the cutter past the cutting edge while such edge is in rotation have been employed, but considerable difiiculty has been encountered due to the fact that the shavings severed from the surface in the finishing process are relatively tough and do not break up, but rather tend to follow the cutter by frictional engagement with its surface thus drawing the rod or tube being operated upon out of proper alignment with the cutter through which it ispasfsing and resulting in a rough, irregular surface on the finished product.

The present invention is concerned with a finishing device of the latter, hollow rotary cutter type, and it is an object of this invention to overcome the problems heretofore encountered with such finishing devices by properly particulating the shavings severed from the body under treatment substantially immediately upon severance 1 from the body and prior to their attaining such length that they might frictionally engage the rotating cutter to such extent as to draw the body out of proper alignment with the cutter. It is a further object to provide a simple arrangement of parts which will facilitate the insertion and removal of cutters so that the device may be conveniently used to finish cylindrical bodies to diameters within a relatively wide range; the

associated mechanism being also conveniently adjustable.

This invention contemplates generally means such as a pair of oppositely rotating contoured rolls, for feeding the cylindrical body to be operated upon, a centering collet adapted to properly axially align and support the body in position for finishing, a hollow rotary cutting member, having a chamfered leading cutting edge, the cutter" being disposed to operate on the surface of the body closely adjacent the supporting and centering collet, particulating means, such as rotating breaker teeth, disposed adjacent the chamfered surface of the cutter effective for engaging the shavings severed from the body by the cutter and for particulation or chipping the same into relatively small pieces, the particulating means preferably rotating at a relatively high speed so as to engage only small increments of shavings, and means, such as a pair of oppositely rotating rolls, for extracting the finished body from the cutter.

In order that the invention may be conveniently understood, reference will be made to the attached drawings, in which Figure 1 is a side elevation of the finishing device;

Figure 2 is a sectional view, partly broken away, showing a cutter and breaker arrangement to enlarged scale; and

Figure 3 is a longitudinal sectional view, partly broken away, of the device of Figure 1.

Referring to Figures 1 and 3, the device comprises a rotatable cutting head 2, a pair of oppositely rotatable feed rolls 3 and 4, a centering and supporting collet 5, a cutter-breaker 6, attached to and rotatable with the cutting head 2, and a pair of oppositely rotatable extractor rolls 1 and 8.

The cutting head -2 (Fig. 3) comprises a central supporting spindle 9 to which is aifixed an integral pulley and bearing support It, the pulley [0 being secured to the spindle 9 by a set screw II. The cutting head 2 is rotatable about ball bearings l2 and I3 carried by a supporting bracket l4 attached to the frame l5 of the machine. The ball bearing details will not be described since they are more or less conventional and form no essential part of the present invention. Any bearing arrangement which preferably permits convenient removal of the spindle 9, as by loosening of the set screw II in the present case, and which accurately supports the cutting head while in rotation at relatively high speed, will be found satisfactory. Rotation is imparted to the cutting head 2 by a motor 6 driving a belt I1 engageable with the face of pulley II].

The cutter-breaker arrangement is best shown in Figure 2. The spindle 9 is provided, integrally with one end thereof, with a threaded, inwardly tapered collet jaw I8. A correspondingly tapered collet jaw I9, having a ground -cutter clamping surface 20 and a limiting flange 2| interengages with the jaw I8 and serves to clamp a cutter 22 in proper axial alignment with spindle 9, the flange 2| serving s an abutment to limit inward and axial movement of the cutter 22. Clamped between the articulated collet jaw I9 and a draw nut 23 is a toothed breaker 24 having an outwardly directed radial flange 25. The draw nut 23 is provided with drilled openings 26 to receive the tooth of a spanner wrench to effect rotation of the nut 23 in assembly and disassembly of the cutter-breaker. When the nut 23 is drawn up, the breaker 24 is clamped securely between the jaw I9 and the nut 23 and the interengagement of the tapered surfaces of the collet jaws causes the jaw I9 to firmly grip the cutter 22.

It will be noted that the cutter 22 has an undulatory leading cutting edge 21 and that the outer surface of the cutter is chamfered, from the cutting edge radially outwardly and downwardly as shown at 28. In order that cutters of the same outer diameter may be used for shaving bodies to different finished diameters, the wall of the cutter is made relatively heavy and the internal wall is ground to the desired diameter, the diameter at the cutting edge of course determining the final diameter of the body being finished. Thus, a series of cutters having the same external diameter may be ground so that their cutting edges will produce a final product of l", 15%", re and 11%; in diameter, for examp e, and only a slight loosening of the draw nut 23 will be required to remove one cutter and insert another of the set. The cutters are all removable by a simple axial movement along the collet jaw IS without any dismantling of the associated parts. To reduce frictional engagement between the shaved body and the cutter, the "body of the cutter is formed to a greater diameter at 29, sufficient body between the recessed zone and the cutting edge 2? being provided to insure proper support of the cutting edge.

The centering and supporting collet is best illustrated in Figure 3. The collet is held in fixed alignment with the cutting head by a support 30 and a clamping ring 3| attached to brackets 32. Firmly fixed by the support 30 and clamp ring 31 is a collet jaw 33 having a tapered surface 33 engageable with a corresponding surface on a collet jaw 34 which is afiixed to a guiding and limiting ring 35 by a set screw 36. The jaw 34 is normally urged to a retracted position, as shown. by a spring 3'! disposed about the jaw 34 between the limiting ring 35 and the jaw 33, thus cornressing the segments of the collet jaw 34.

The feed rolls 3 and 4 and the extractor rolls 1 and 8 are of similar character and, accordingly, only one set will be described. The rolls 3 and 4 are mounted in end bearings 38 and 39 (Fig. 1) moveable in ways 40. The bearing blocks 38 and 39 are connected by a lead screw 4|, the portion passing through one bearing block being of right hand and the portion passing through the other being of left hand. The lead screw carries a worm wheel 42 keyed thereto. A similar arran ement is provided on the opposite ends of the rolls 3 and 4 and a cross shaft 43 has keyed thereto worms (not shown) engageable with the worm wheels 42 carried. by the lead screws M. A hand wheel 44 is provided for rotating the cross shaft 43 and rotation is effective, by reason of the right and left hand threading of the lead screws, to move the rolls 3 and 4 with respect to each other to accommodate bodies of varying diameter. The rolls 3-4, 'I8 are contoured as indicated in Figure 3 so as to engage a relatively large portion of the surface of the body being operated upon thus aiding the collet 5 in proper centering of the body being operated upon to insure that the finished product, if it be hollow, will have a uniform wall thickness.

The rolls 3 and 4 are mounted on ways for movement toward and away from the cutting head 2 so as to facilitate replacement of the cutters 22. A rack 45 is secured to the roll standard or frame 46 and an intermeshing pinion 41 is secured to a shaft 48 affixed to the frame I5 of the machine and the shaft is provided with an opening 49 (Fig. 1) to receive a crank for imparting rotation to the shaft 48 and pinion 41, moving the roll standard 46 along its ways toward or away from cutting head 2. The collet 5 may then be moved away from the cutter head 2 by loosening the 'clamp ring 3| and axially displacing the collet,

thus providing ample space for the removal of the cutter 22 and insertion of a replacement.

Rotation is imparted to the feeding and extracting rolls 3-4 and 1-8 by motor I6 which is provided with a reduction geared head 50 which drives a sprocket 5 I. A somewhat larger sprocket 52 is secured to roll 4 and a chain 53 imparts rotation from sprocket 5| to sprocket 52. To insure uniform rotation of all of the feeding and extracting rolls, each has secured thereto a sprocket 54, and a chain 55, which meshes with each of the sprockets 54, imparts motion thereto. It will be observed that chain 55 travels over one sprocket and under the other of each pair for the feeding and extracting rolls so as to impart the necessary reverse rotation to the rolls of each set. Chain 55 passes over an idler sprocket 56 and a similar idler sprocket 5'1 attached to abifurcated threaded arm 58 serving to adjust the tension on chain 55 by rotation of hand wheel 59. This arrangement is necessary also to permit loosening of the chain upon movement of the roll standard 46 in replacement of cutters 22.

In the device shown in the drawings there is but a single cutting head shown since my invention may be conveniently understood from a description of a single unit. It is desirable, however, to provide a series of cutting heads and feeding and centering collets mounted in tandem and provide a single set of feeding rolls and extracting rolls therefor, such rolls being provided with properly contoured surfaces to engage a series of tubes or rods being operated upon to feed the same to and extract the same from their respective supporting and centering collets and cutting heads.

In the operation of my device, the tubes to be operated upon are placed upon a supporting table 66 and are entered into the nip between the feeding rolls 3 and 4 which force the tube into the mouth of the centering and supporting collet 5, frictional engagement of the outer surfaces of the tube with the surface of the collet jaw 34 causing the same to move to the right as viewed in Figure 3 and the segments to expand radially until the frictional engagement therebetween is such that the tube may be moved therethrough by the driving force of the feeding rolls 3 and 4, the retractive force of the spring 31, however,

bein sufficient to impart a firm grip to the tube by the segments to insure proper axial alignment, the collet being yieldably expansibl to compensate for irregularities in the tube being operated upon. The tube adjacent its outer surface is engaged by the leading cutting edge 21 of the cutter 22 which is rotating at about 1800 revolutions per minute, While the tube being op erated upon is held against-rotation by engagement with the centering and supporting collet and the driving rolls 3 and 4. As the tube is forced into the cutter 22, the thin surface layer of the tube which is removed by the cutting edge 2'! rides along the tapered surface 28 of the cutter 22 and, due to the fact that the material possesses very little strength when severed into' thin sections, it splits longitudinally into about four irregularly edged segments or shavings which move along the surface 28 and are immediately engaged by the toothed breaker 24 which, being fixed to the cutter head, is rotating at the same speed as the cutter 22, namely, 1800 revolutions per minute. The teeth on the breaker 24 are disposed so that the cutting or breaking surfaces 24' thereof face in the direction of travel of the breaker. The result is that the irregularly edged segments are broken or torn into relatively small pieces and there is no tendency for the tube to be sprung out of the axially aligned position it assumes with respect to the cutter 22. The breaker 24 rotates so rapidly that its teeth 24' engage only small sections of the severed segments and the shearing or breaking action is substantially uniform on each segment so that there is no tendency to draw the body out of alignment. Heretofore, when the irregularly edged segments were permitted to flow as long lengths from the body from which they were severed, they would become wrapped around the cutter by frictional engagement therewith and the drag would tend to draw the tube being operated upon out of axial alignment.

It will be noted by reference to Figure 2 that the breaker 24 is spaced radially slightly from the periphery of cutter 22. This spacing is provided to permit proper axial alignment of the cutter upon insertion into the collet without interference from the breaker 24. The space between the elements is not large enough, however, to permit the severed segments'to become lodged therebetween.

' As the feed rolls 3 and 4 continue to move the tube through the collet 5 and the cutting head 2 along spindle 9, the forward or leading end of the tube is engaged by the contoured surfaces of the extractin rolls 1 and 8 and, after the tube leaves the feeding rolls 3 and 4, the extracting rolls 1 and 8 are effective for drawing the remaining portion of the tube through the collet 5 and the cutting head 2, thus completing the finishing operation.

It is obvious that when operating at the speeds indicated above with a relatively frangible material such as cork composition the teeth 24' on be sharpened so as to actually sever the material to particulate it. In place of teeth a series of pins or other abutments may be provided so as to rotate with the cutter and be disposed adjacent the chamfered surface 28 and engage the segments severed from the body as they travel along the inclined surface of the cutter, serving as the tooth breaker to particulate the severed surface layer and avoid any drag on the'body being operated upon which would cause it to become misaligned with respect to the cutter. cork composition finished -with the cutterbreaker arrangement shown in the drawings have a smooth surface, free of irregularities and a relatively uniform wall thickness is obtained. While I have illustrated and described certain preferred embodiments of my invention, it will be understood that the same may be embodied and practiced within the scope of the following claims.

I claim:

1. A cutter mechanism for finishing the outer peripheral surface of cylindrical cork composition bodies by removal of a thin annular shaving therefrom, said cutter mechanism including a rotatable cylindrical cutter through the bore of which the body may pass, said cutter having a leading cutting edge to sever a thin annular shaving from the body as the body passes through the cutter, said leading edge being tapered from the inner periphery of the cylindrical cutter outwardly and away from the leading dge thereof, said taper being sufiicient to engage and guide the annular shaving, as it is cut, away from the cutter and rupture it into segments, and obstructions secured to said outter, rotatable therewith, spaced around the periphery thereof, and projecting toward the leading edge into the path of said segments, whereby, as said obstructions rotate, they will engage the longitudinal edges of the segments and knock them free from the continuously cut annular shaving, said cutter mechanism thereby cutting the shaving and particulating the shaving as it is cut. I

2. A cutter mechanism in accordance with claim 1 in which the rotatable cylindrical cutter has an undulatory leading cutting edge.

3. A cutter mechanism in accordance with claim 1 in which the obstructions are disposed as teeth having abutting surfaces substantially parallel with the axis of the cutter, with the axially extending surfaces connected by inclined surfaces.

4. A cutter mechanism in accordance with claim 1 in which the obstructions are in the form of an annular breaker which is secured to the cutter but spaced radially therefrom in the vicinity of the cutting edge. 7

5. A cutter mechanism in accordance with claim 1 in which'the rotatable cylindrical cutter is secured within a collet jaw and in which the obstructions are in the form of a toothed breaker which breaker is secured in position about the periphery of the cutter but spaced radially therefrom, the cutter being removable from the assembly without removal of the toothed breaker.

LUTHER E. GAENZLE.

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